Antibiotics, such as clarithromycin and erythromycin has been used in the treatment of common pediatric infections of the middle ear and upper respiratory tract, as well as certain forms of pneumonia that affects the elderly. Formulations containing an antibiotic are typically administered as immediate-release compositions, two or three times a day, for a regimen of 10-14 days. However, such antibiotics are extremely bitter, and even when dissolved in trace quantities in a liquid dosage form are often perceived to be unpalatable. One approach to improve the possible non-compliance with the immediate-release compositions has been to develop controlled-release solid preparations containing the antibiotic.
U.S. Pat. No. 4,842,866 describes an extended-release pharmaceutical formulation containing an active drug ingredient, sodium alginate and sodium-calcium alginate. The active drug ingredient is present in an amount up to 70% by weight of the formulation.
U.S. Pat. No. 4,808,411 describes a taste-masked composition in the form of granules which contain 25% to 90% of erythromycin or a derivative thereof, and 5% to 75% of an acrylic acid polymer.
U.S. Pat. No. 4,389,393 describes a sustained-release therapeutic composition containing an active agent and from 5 wt. % to about 30 wt. % of hydroxypropylmethyl cellulose or a mixture of hydroxypropylmethyl celluloses.
International Application WO 03/017981 describes controlled-release formulations containing a drug having a water solubility of less than 1 part per 30 parts water, and from about 0.1% w/w to about 4.5% w/w of a rate-controlling, high-viscosity cellulosic ether polymer.
International Application WO 02/017885 describes a controlled-release pharmaceutical composition containing erythromycin A or a derivative thereof and from about 0.1% w/w to about 4% w/w of a rate-controlling polymer. Examples of rate-controlling polymers are a carbohydrate gum, polyuronic acid salt, cellulose ether and acrylic acid polymer.
U.S. Pat. No. 5,286,489 describes a porous drug-polymer matrix formed by admixing one or more bitter tasting active ingredient and a methyl methacrylic ester copolymer in at least a 1:1 by weight ratio of active ingredient to copolymer. U.S. Pat. No. 5,286,489 states that an effective taste making amount of the copolymer is used.
U.S. Pat. No. 6,565,877 describes a taste-masked composition containing a bitter tasting drug, such as clarithromycin, and a combination of two enteric polymers comprising a methacrylic acid co-polymer and a phthalate polymer. U.S. Pat. No. 6,565,877 states that for optimal taste masking effect, total polymer to drug ratio is at least 1:4.
U.S. Pat. No. 6,010,718 describes an extended-release composition containing an erythromycin derivative and from about 5% to about 50% by weight of a pharmaceutically acceptable polymer.